Pediatric Vision Screening Assessment

Stress Theory (Physics)

• Stress is the force causing deformation in a body.
• Strain is the resulting deformation.
• Stress is the cause, strain is the effect.
• In everyday speech, we use "under stress" but stress is still the effector.

Hans Selye's Stress Theory

• Stress is the body's response.
• Stressors are the factors triggering the response.
• The response is non-specific to any demand on the body.
• Emphasizes stress as a response/reaction to something.
• Any agent/event/circumstance can produce this response.
• This response is non-specific.

Influences on Adaptation

• Stress affects individuals differently.
• The same individual may respond to stress differently at different times.
• Stress tolerance varies between individuals.
• Interacting factors influence stress responses.
  • Stressor variables (type, persistence, intensity, concurrent conditions).
  • Genetics, external factors (temperature, pollution, noise).
  • Psychological factors (personality, attitude).
  • Prior conditioning.

Skeffington's Model of Vision

• Includes centering, antigravity, identification, and speech-auditory.

Skeffington's Four Circles

• Antigravity System (Vestibular):
  • Basic frame of reference for orientation and spatial localization.
  • Provides internal balance and position in space.
• Centering (Convergence):
  • Directs body, head, and eyes to process information within a given space.
  • Focuses attention and orientation in external space.
• Identification (Accommodation):
  • Collects meaning from areas of attention in external space.
  • Determines relationships between details.
  • Differentiates and discriminates details.
• Speech-Auditory:
  • Analyzes what is seen and communicates the information.

Nearpoint Stress Model

• Humans are biologically unsuited for near-vision tasks.
• Demands for sustained concentration, immobilization, and mental effort provoke a stress response.
• Centers on a drive to localize closer than accommodation.
• Vergence and accommodation need to converge at the plane of regard.
• The drive for vergence to localize closer than accommodation leads to blur or diplopia.
• Common choices are avoidance, inefficient visual function, or accommodative/vergence adaptation.

### Options for Nearpoint Stress Model
-  Avoidance
- Inefficient visual function
- Accommodative or vergence adaptation.

COVID Quality of Life (QOL) Questionnaire

• Developed by a committee in 1995.
• Assess changes via vision therapy, change in distance spectacle RX, use of near-point lenses.
• Original version: 30 questions.
• Shortened version: 19 questions.
• Advantages include ease of administration, low cost, and standardization.
• Disadvantages include limited clinician elaboration opportunities.

Scoring for COVID QOL Questionnaire

• Scoring system uses point values for responses ("always"=4 points, "frequently"=3, "occasionally"=2, "seldom"=1, and "never"=0).
• Totals are calculated by summing scores from each question.

• 20 indicates potential visual efficiency or perceptual disorder.

Cover Test

• Detects strabismus (eye misalignment).
• Unilateral test or alternating test.
• Alternating tests can detect phoria.

Phoria Measurement (Von Graffe)

• Used in a phoropter.
• Used to determine lateral and vertical phoria.
• Letters must be clear at all times.
• Norms for distance are 1 XP +/-1.
• Norms for near are 2 XP +/-2.

Near Point of Convergence

• Measures convergence amplitude, objectively and subjectively.
• Determines break and recovery.
• Break and recovery become more reduced in patients with binocular vision issues.
• Different targets used (e.g., 5cm break, 7cm recovery, penlight with red lenses, etc.).

Smooth Vergence

• Measures the amplitude of the fusional response for both positive and negative vergence.
• Focuses on blur findings to determine accommodation changes.
• Includes accommodation and accommodation-free break and recovery.
• Focuses on the patient's ability to regain fusion following diplopia.

Stereo Testing (Various tests)

• Measures the degree and presence of stereopsis.
• Includes local/contour stereopsis, Wirt circles, Titmus stereofly, animals (all using laterally displaced targets), monocular cues.
• Helps determine peripheral stereopsis presence, and helps detect constant strabismus.

Prism Facility

• Assesses the vergence system's response over time.
• Measures vergence stamina.
• Relates to accommodative amplitudes and facility.

Accommodative Testing

• Measures amplitude (push-up, pull-away, minus lens-to-blur).
• Tests facility (monocular, binocular).
• Includes response testing (MEM, FCC).

Hofstetter's Formulas

• Based on Donders and Duane's work.
• Target is a single black line.
• Used to calculate minimum and average accommodation.

Accommodative Amplitude

• Measures push-up vs. pull-away.
• Materials use a near point card or fixation target (with tongue depressor and accommodative target).
• Monitor patient response (facial expressions, child moving away from target).
• Compare to Hofstetter values.

Accommodative Facility (various assessment components)

• Measures the ability to clear minus and plus lenses, observing for accommodative insufficiency, convergence excess, accommodative excess, convergence insufficiency.
• Recording should include performance deterioration during testing, suppression occurrence/what is required to clear, postural changes (chair slumping, head tilt), and patient complaints (attempting to move card).

Accommodative Posture

• Assesses accommodations.
• Uses objective tests, determining accommodation posture or lag.
• Provides an appropriate near vision RX.
• Determines whether the accommodative posture has high or low demand, adjusting the testing accordingly.
• Verifies findings and notes whether lens speed is crucial.

NRA/PRA

• Indirect measure of accommodation.
• Binocular procedure (patient wears habitual RX).
• Target placement: 40 cm.
• Testing with plus/minus lenses, recording blur response/reporting the first sustained blur.

AC/A Ratio

• Determines the change in accommodative and vergence on relaxation/stimulation.
• Calculated from IPD(cm)+NFD(m)(Hn-Hf), and uses Gradient/Phoria methods with +/-1.00.
• Calculated value is typically higher than gradient due to the effect of proximal vergence, lowering gradient results.

Eye Movements

• Fixation: Direct observation test; patient sits, and then shifts to monocular observation. -Uses SCCO grading (evaluates smooth and accurate fixations, 3-one loss, etc.)
• Pursuit: Direct observation test; patient stands and target is moved in clockwise and counter-clockwise directions.
  • Uses NSUCO grading, evaluating ability and accuracy, head/body movements.
• Saccades: Direct observation test; patient sits and two targets, 20-25 cm apart, are used, monitored during 5 round trips.
  • Uses NSUCO grading, evaluating ability and accuracy, head/body movements. Uses SCCO for observation.

King-Devick Saccadic Test

• Evaluates reading eye movements.
• Procedure: Patient calls out 40 numbers horizontally.
• Grading: Based on the number of errors and the time taken.
• Three different levels for the test.

Developmental Eye Movement Test (DEM)

• Reading eye movements; considered a visual-verbal test.
• Uses vertical and horizontal arrays testing recall and eye-tracking.
• Grading is based on errors, types of errors, time taken in sections.
• Four possible results— -No deficit (motility/automaticity) -Ocular motility dysfunction -Automaticity problem. -Automaticity and OMD dysfunction.

Visagraph/Readalyzer

• Objective test of reading eye movement.
• Goggles have infrared sensors that detect eye movement, which is then processed by a computer.
• Results include fixations, regressions, backward jumps, reading rate, fixation duration, recognition spans, directional attack, efficiency, and grade equivalent.

Near Point Stress Model questions/answers

• How does stress cause vergence to localize closer than accommodation?

• As per the AC/A ratio, when vergence is stimulated, accommodation is stimulated, ramping it up further.

• What is a buffer in this case?

• Hyperopia and exophoria act as visual system buffers.

Adaptation to Visual Stress

• Signs of adaptation include— -exophoria or esophoria -low or high MEM or fused crosscylinder -low absorption of hyperopic buffer -NRA/PRA both less than 1.75
• Myopia/emmetropia will decrease the hyperopic buffer, decreasing accommodation, and associated over-convergence.

General Management Approach

• Most appropriate Optical Correction: -Plus at near or prism for visual stress relief.
• Vision Therapy and Visual Hygiene: -Maintain good posture. -Take good breaks. -Use good lighting. -Slant reading material.

Treatment Strategies (plus at near):

• Determine if plus helps relieve symptoms based on low AA, eso at near, low PRA, high lag on MEM/FCC, and higher NRA than PRA testing.
• Calculate—Add PRA and NRA and divide by 2, which is the target add power.
• Conditions that respond to plus include accommodative insufficiency, ill-sustained accommodation, and symptomatic esophoria at near.

Three Cheers for Plus at Near

• Includes patient information, COVD checklist details, VA, stereo, cover test, phoria, EOMS, NPC, and accommodative amplitude.

CI-A prism disaster

• Case of a patient that was complaining of headaches, blurry vision, and intermittent diplopia.
• Patient's history included challenges with reading, an increase in prism power over time, and previous treatment with bifocal lenses.
• Includes various details for diagnostic testing (VA, stereo, cover test, phoria, retinoscopy, and NPC).
• Treatment includes prescription changes, and vision therapy.
• Follow-up testing is recommended.

Too much plus is a bad thing!

• Case of a patient (9-year-old female) who is complaining of blurry vision at distance and has good vision without glasses.
• Includes testing findings (VA, stereo, cover test, NPC, retinoscopy, and MEM), the trial frame RX, and a follow-up recommendation.
• Includes details for possible DEM testing results, which showed time taken with and without Rx adjustments.

Sudden Vision Decrease

• Case of a 9-year-old female with sudden vision decrease, issues with reading, and no headaches when reading. -Includes various details regarding testing (VA, PERRLA, confrontations fields, EOMS, Stereopsis, Hirschberg, NPC, retinoscopy, internal/external health review). -Follow-up testing is recommended.
• Includes VEP testing and results.
• Includes diagnosis of Streff syndrome.

• To Rx or not to prescribe? that is the question! :

• Includes various details of testing (VA, cover test, stereo, retinoscopy).
• Includes possible recommendations/prescription choices based on developmental recommendations.

This quiz assesses your understanding of pediatric vision screening results. It includes questions on visual acuity, retinoscopy outcomes, prescribed conditions for failures, and measurements like Stereopsis and Near Point of Convergence. Test your knowledge of how to interpret these critical vision assessments.